HELP ME IM ON A TIME LIMIT PLS

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?

What three-dimensional solid have 6 rectangular faces, 2 equal bases that are not rectangles and 18 edges